1. Field of the Invention
The present invention relates to the field of fenestration products including windows. In particular, the invention is concerned with a tiltable window sash and a brake for preventing slidable movement of the sash while in the tilted position.
2. Description of the Prior Art
Double hung windows with tiltable sashes provide an advantage in that the sashes can be tilted inwardly for convenient cleaning, repair or replacement. These types of windows include a balancing assembly such as springs or the like that balance the weight of the sash. In the tilted position, the top rail of the sash is supported and less weight is presented to the balancing mechanism. As a result, the balancing mechanism causes the bottom rail, which is still engaged between the jambs, to slide up the jambs.
The prior art discloses a variety of brake mechanisms for preventing movement of the sash while in the tilted position. These prior art mechanisms tend to be mechanically complex resulting in additional manufacturing expense and the potential for mechanical failure.
In one prior art device, ellipse-shaped cam elements extend from the stiles into respective jamb channels at the ends of nail-like fasteners with the interior end driven into the wood of the stile. When the window is tilted, the long axis ends of the cam elements engage the side walls of the channels to brake the movement of the sash. The cam element has a tendency to damage the side walls of the channel and only engages after the window is tilted about 30.degree.. This allows sliding of the window until this position is reached. Also, the fastener tends to loosen over time allowing the cam element to rotate with a resulting loss in braking effectiveness.